Calculate the intensity of light given the power and area over which it is distributed. Applies to point sources using the inverse square law.
Enter your values below
Total power emitted by the light source.
Area over which light is spread. Leave blank if using distance.
Distance from point source. Area = 4*pi*r^2 is used if area is blank.
How this calculator works
Light intensity I is the power P per unit area A. For a point source radiating uniformly, I = P / (4 * pi * r^2), where r is the distance from the source.
Common questions about this calculator
These calculators are for educational and informational purposes only. While we strive for accuracy, results should be verified for critical applications. Always consult authoritative sources for engineering or scientific work.
